It is known that improvements in vehicle performance and fuel consumption can be achieved through improvements in the aerodynamic structure of a vehicle. Such improvements are sought in the design of vehicles in the haulage industry, for example articulated vehicles of the kind having a cab and trailer.
GB2443035 describes a road haulage vehicle (with cab and trailer) having a curved roof profile which purports to improve the aerodynamic efficiency of the trailer. However, such systems have been found to be optimal when used with rigid vehicles because there can be large aerodynamic inefficiencies when used with articulated trailers.
Generally tractors usually have adjustable height fairings, the fairing cannot operate optimally at all positions of the fairing. Indeed, in some fairing positions there is a large reduction in aerodynamic efficiency.